This invention relates to movable electric machinery having a trailing cable connected to a source of power. More particularly, this invention relates to a mechanism for preventing the cable from contacting the movable electrical machinery as the machinery moves forward, backwards, and around corners.
Movable electrical machinery, such as shuttle cars used for carrying mining material in underground mines, have electric motors connected by a cable to a source of power. As the machinery moves backwards, forwards, and around corners, the cable is either wound onto or paid out of a reel. The cable extends from the rear of the shuttle car, and, at times, either runs along the side of the shuttle car, when the shuttle car is moving backwards, or extends straight back from the shuttle car, when the shuttle car is moving forward. When the shuttle car moves around right corners, the cable runs along the rear of the shuttle car.
In order to prevent the cable contacting the side or the rear of the shuttle car, a two-sheave bracket assembly has been fixed on the left rear of the shuttle car. One sheave extends just beyond the rear most part of the shuttle car on one side of the shuttle car, and the second sheave, spaced from the first sheave, extends outward from the side of the shuttle car. In this manner, the cable either extends around one sheave and across the rear of the shuttle car when the shuttle car is making a 90-degree right turn, or the cable extends around the other sheave and back along the side of the shuttle car when the shuttle car is moving backwards. The current sheave bracket assembly arrangement is limited as to how far it can stick out of the side of the machine, otherwise the bracket assembly could be damaged by the bracket contacting the wall of the mine. Furthermore, the sheave bracket assembly cannot extend too much rearward of the shuttle car or it will affect the turning radius of the machine.
The invention provides a movable machine including a frame having an end, an electrical motor on the frame, a cable electrically connected to the motor and adapted to be connected to a source of power, and a sheave bracket assembly mounted on the frame end. The sheave bracket assembly includes a mounting plate, two spaced apart sheaves rotatably mounted on the mounting plate, the cable extending between the sheaves, and hinged means connecting the mounting plate to the frame end for permitting pivotal movement of the mounting plate relative to said frame.
More particularly, the invention provides a movable machine including a frame, an electrical motor on the frame, a cable electrically connected to the motor and adapted to be connected to a source of power, a reel on the frame between the electric motor and one end of the frame, the reel providing storage of the cable, a spooling device between the reel and the one frame end, and a sheave bracket assembly mounted on the one frame end. The sheave bracket assembly includes a mounting plate, and two spaced apart sheaves rotatably mounted on the mounting plate. The cable extends between the sheaves. A second mounting plate is parallel to and spaced apart from the first mounting plate, and the two spaced apart sheaves are also rotatably mounted on the second mounting plate.
The sheave bracket assembly also includes hinged means connecting the mounting plates to the frame end for permitting pivotal movement of the mounting plates relative to the frame. The hinged means comprises an arm including a first Y-shaped part with its base attached to a first pivot mount connecting its base to the frame end, and each upper Y piece includes four wire ropes attached thereto and attached to a second pivot mount connecting the four wire ropes to the mounting plate. The second pivot mount includes a lower pivot connection to the first mounting plate and to one of the upper Y pieces, and an upper pivot connection to the second mounting plate and to the other of the upper Y pieces.
The hinged means also includes a second arm including a first Y-shaped part with its base attached to another first pivot mount connecting its base to the frame end. Each upper Y piece includes four wire ropes attached thereto and attached to another second pivot mount connecting the four wire ropes to the mounting plate. This other second pivot mount includes a lower pivot connection to the first mounting plate and to one of the second arm upper Y pieces, and an upper pivot connection to the second mounting plate and to the other of the second arm upper Y pieces.
Still more particularly, the movable machine further includes a first resilient stop attached to the frame end adjacent the first pivot mount and a second resilient stop attached to the frame end adjacent the other side of the first pivot mount.
One of the principal objects of the invention is to provide a hinged sheave bracket assembly. A hinged sheave bracket assembly permits further extension of the sheave bracket assembly to the side of the shuttle car.
Another of the principal objects of the invention is to provide a hinged sheave bracket assembly mounted on flexible arms. The flexible arms reduce the stress put on the cable as the machine moves and changes direction. Further, if the sheave bracket assembly should engage the mine wall, the flexible arms help reduce the likelihood of damage to the sheave bracket assembly.